圆柱突然启动后绕流的最小二乘等几何模拟 Least Squares Isogeometric Method for Transient Flow around an Impulsively Started Circular Cylinder

为研究最小二乘几何方法处理较复杂流动的特性，用该方法求解了圆柱突然启动后的瞬态流场。控制方程的时间离散采用三阶精度的隐式差分格式，空间离散采用二阶以上精度的最小二乘等几何方法。对雷诺数为550~9500的流动进行了模拟，并与其它实验及数值方法的结果进行了对比，数值解中捕捉到了不同雷诺数下的产生的鼓包、孤立涡、α-现象和β-现象等流动模式。计算结果表明高精度的最小二乘等几何法可用于复杂瞬态流动的模拟。 To investigate the capability of least squares isogeometric method for complex flow, the method was used to simulate the transient flow around an impulsively started circular cylinder. The governing equations were first discretized in time by implicit difference scheme with third order of accuracy, and then discretized in space by least squares isogeometric method with order of accuracy more than two. The flow over a range of Reynolds numbers from 550 to 9500 was numerically simulated. Results were compared to those from other experimental and computational works. The flow modes like bulge, isolated secondary eddy, α-phenomena and β-phenomena at different Reynolds number were resolved correctly. The results show that the high order accuracy least squares isogeometric method can be used for simulation of complex transient flow.